Thanks, is Ioann the closest translation from Russian? How would you pronounce that name 
I found something on the etymology:
IOANN m
Usage: Russian
Older Russian form of JOHN
IVAN m
Usage: Russian, Czech, Croatian, Slovene
Pronounced: IE-van
Russian, Czech, Croatian and Slovene form of JOHN. This was the name of several rulers of Moscow, including Ivan the Great and Ivan the Terrible, the first czar of Russia. Other notable bearers include Ivan Turgenev, a Russian author who wrote 'Fathers and Sons', and Ivan Pavlov, a scientist and physiologist best known for his discovery of the conditioned reflex.
Ioann (m) -- The Russianization of John (God is gracious) and one of the most common given names. Both the older form (Ioann) and the newer (Ivan)
I'll have to look for the pronunciation. It seems KR with his deep religiosity combined with his love of culture & history wanted to reach way back for a name. Ioann was the son of Ivan the Terrible.
Some of KR's other children:
Gavril (m) -- Russianization of Gabriel ("my strength is God").
Vysheslav (m) -- "high glory." Vysheslav, son of Saint Vladimir.
Tatiana (in addition to being from Eugen Onegin)
Tat'iana (f) -- "to designate." Tat'iana, martyr. 1356.